Why does the remedial class always call me inexplicably to ask how old the child is, and I am the one who can't get married at the age of 20?

One possibility is that your phone number has been leaked to the relevant institutions. One is that the last householder on your phone number has children, and you used this number to contact the remedial class or something.

Often encountered. I am in the second case, which is very difficult, because this is the phone number left by the counseling agency. If there is any activity in this area, I will definitely call. If you receive it, it clearly means that the number has been changed and it is not the person you are looking for. Avoid them calling again next time. Don't hang up directly, or they will call again next time. Or you can just mark it and paint it black.